Im setting up a 90 reef softie and fish. I like simple. When picked up the tank I got almost 300 pounds of live rock (dry). 2 pieces are very large. I was wondering if could lay the flat one on the bottom or should I put in the sump?
I would break that large piece and use it in your rock scape or sump.
Why is the rock green, have these rocks been used before, and then allowed to dry out? If so, you may want to cure them first before starting your new tank with them.